Yes, of course you can always use the Windows ‘Auto hide’ feature to hide the taskbar and it will re-appear only when you place the mouse bottom of the desktop. But, here is a simple utility with a difference for hiding the taskbar in Windows 7.The portable utility called Hide Taskbar lets you hide only the taskbar, and not the Start Button, with a hot key.
Using this program is extremely simple. Download and extract the program. Run the app. Use hotkeys Ctrl+Esc to hide or un-hide the taskbar.
Download Hide Taskbar